US3785866A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for avoiding pitting in plating oxide-film-developing metals
Assignee: OAKITE PRODUCTS Inc A DE CORP
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Filing: 1972-08-14
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Granted: 1974-01-15
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Expires: 1992-08-14
Abstract
Abstract The tendency to blistering and related adverse effects on adhesion of protective coatings to be applied over the surface of a metal oxidizable by anodization and capable of taking an electrodeposit, is reduced by forming an anodic film on the metal surface, and then removing that film with any natural oxide film on which it may have been formed, by immersing the oxidized surface in an aqueous pickling bath containing dissolved inorganic ferric salt, sulfuric acid or a bisulfate, and an inorganic fluoride.
Inventors
- 👤 S Frey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:33
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/34; C23; C23G; C23G1/00; C23G1/02; C23G1/10; C25D5/00; C25D5/34; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9335; Y10S428/934; Y10S428/935; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12785; Y10T428/12792
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
50 words
The method as claimed in claim 1, wherein said pickling bath contains dissolved in its water from about one to five percent by volume of an aqueous solution containing about 22.5 percent of ferric sulfate, about 23.5 percent of 66* Baume sulfuric acid, and about 1.8 percent of hydrogen fluoride.
Claim 2
Dependent Claim
53 words
The method as claimed in claim 2, wherein said bath contains in percentages by weight thereof, from about 0.06 to about 0.33 of ferric ion, from about 0.01 to about 0.114 of fluoride ion, from about 0.52 to about 1.96 of sulfate ion, and from about 0.009 to about 0.190 of hydrogen ion.
Claim 3
Dependent Claim
68 words
The method as claimed in claim 1, wherein said pickling bath contains by weight from about 0.18 to about 0.54 percent of ferric ion provided by crystalline ferric sulfate, from about 0.59 to about 1.76 percent of sulfate ion provided by sodium bisulfate, and from about 0.006 to about 0.018 percent of fluoride ion provided by sodium bifluoride, and the pH is from about 1.2 to about 2.5.
Claim 4
Dependent Claim
36 words
The method of reducing the tendency to blistering and related adverse effects as claimed in claim 4, wherein the ferric salt is ferric sulfate, the bisulfate is sodium bisulfate, and the fluorine-element-containing compound is sodium bifluoride.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |